“So, what are you going to do?” says Lucy, played by Melissa Leo, to her neighbor Mildred, played by Kate Winslet. “You just joined the biggest army on Earth. You’re the great American institution that never gets mentioned on the 4th of July. A grass widow with two small children to raise on your own.

“The dirty bastard.”

The new HBO miniseries, which debuts at 8 tonight, is deeply loyal to James M. Cain’s 1941 novel and to the place and period in which it’s set, Los Angeles during the Great Depression.

“The set was so beautiful, and every person, down to their shoes and shoelaces, dressed to the period,” Leo said during a recent interview. “When we’d walk on the set, this environment had been created: the extras, the day players, the other actors, their willingness to step back in time ...”

And, she added, “The language was so beautiful.”

Beautiful in a hard way, thanks to Cain (“The Postman Always Rings Twice,” “Double Indemnity”), and Leo gets to deliver a lot of it as neighbor-lady and confidant to Winslet’s Mildred.

One great line she doesn’t get to say comes from one of Pierce’s kids, reacting to sentimentality like a grizzled noir detective: “Cut the mush.”

It’s a phrase that could serve as a subtitle for the whole project.

Shot entirely in New York, co-written and directed by Todd Haynes (“Far From Heaven,” “I’m Not There”), it’s Winslet’s vehicle all the way. Pierce’s travails with men, her chain of chicken restaurants and those two girls, one of which is a demonic diva, fill more than five hours of air time over three Sunday nights.

The HBO miniseries shares only a little with the 1945 film noir classic of the same title, which was Hollywoodized into a thriller that won Joan Crawford an Oscar.

For example, Leo’s Lucy is a key character in both the book and miniseries but didn’t make the film’s screenplay, to which William Faulkner contributed.

Lucy is a woman who’s “a little ahead of her time,” Leo said, and a participant in “a network among women that I know has gone on from the beginning of time that still goes on today.

“We see in men all kinds of hurly-burly ways, in the way men work together, that’s quite aggressive,” she added. “Women go not without their arguments about things, and differing ideas, but it’s in that network of triangulation, spider- webbing. ‘Jeez , you can get a lot done.’”

The miniseries started shooting before the first season of “Treme” wrapped.

“I was doing the Toni-Lucy dance for awhile,” Leo said, adding it was a dance made easy by her local employers. “I’ve never known anyone who knows and respects actors as much as (“Treme” production company) Fee Nah Ney.”

The opportunity to work with Winslet was Leo’s “first attraction to the job, before I knew too much about it,” she said.

The experience “fulfilled my expectations and so much beyond,” she added. “She’s a fabulous actor, one of the very best actors to work with.”

Haynes was another attraction, but Leo also had a personal connection to the story.

“My great grandmother owned and ran a chicken pie shop in southern California” during the time depicted in the miniseries,” Leo said. “No joke. It was the livelihood of the family for a time. They had been farmers. That harkens back to something so strongly for me.

“And then I met Todd. He, to me, is the definition of director.

“Everything about that job was so glorious.”

Dave Walker can be reached at dwalker@timespicayune.com or 504.826.3429. Read more TV coverage at nola.com/tv. Follow him at twitter.com/davewalkertp.